Production of ammonia.



I 1 I I K'JARL BOSCH AN'D ALW'IN MITTASCH', OF LUDWIGSHZAFEN-ON-THE-RHINE, GERMANY,

ASSIGNDRS T BAIDISCHE ANILIN do SODA FABRIK, OF LUDWIGSHAFEN-ON-THE- .RHINE, GERMANY, A. CORPORATION.

PRODUCTION-01: ammonia.

' Specification of Letters Patent. Application filed November 11, 1912.

messes.

Itc Drawing.

121 whom it may goncem:

5e itknown that we, CARL Boson and AL'WIN Mirrason, subjects, respectively, of

the King ofcPrussia and the King of Saxpny, residing at Ludwigshafenmn-theiii-line, Germany, have invented new and useful Improvements in the Production of Ammonia, of which the following is a specification.

We have discovered that we can obtain ammonia in good yield while making use of gaseous nitrogen and hydrogen, by passing the said gases successively and periodically over a catalytic agent which contains two or more metals and which is capable of combining directly with at least one of the two gases nitrogen and hydrogen. Insteadof one .or more-of the metals themselves, a ni trogen or hydrogen compound thereof can, in some cases, be employed, since during the progress of the reaction such'compounds may be formed. Consequently, for the purposes of this invention, nitrogen and hydro gen compounds of the metals are to be re garded as the equivalents of the metals themselves. Instead of starting with the metals themselves, compoundsthereof, such for instance as their jcarbids, can be employed, which during the reaction give rise to the metals or their nitrogen or hydrogen compounds. If the mixture, or one of the constitutents thereof, be adversely affected,

by-oxygen or water vapor, precautions must be taken to prevent this occurring and also steps must be taken to prevent the presence of contact poisons. If desired one or more than one body which will promote the power of, the mixture, as described in the specifications of British Patents, Nos. 19,249/1'0, 5833 and 5835/11, may be added to the mixture. We prefer generally to employ temperatures not exceeding 600 C. during the production of the ammonia and it is sometimes advantageous to employ different tem peratures during the two periods of passing the nitrogen and hydrogen respectively over the mixture. As particular instances of mixtures of metals which are capable of use according to our invention, we mentionmonia is formed and can be absorbed from Patented Feb. is, rare. Serial No. 730,645.

' regard our invention as being restrictedto such mixtures.

The following eirample will serve toillustrate further the nature of ourinvention, which, however, is not confined to this example: Pass a current of nitrogen, which may contain small quantities of hydrogen without departing from the nature of our invention, into a vessel containing lithium, manganese nitrid, at from 450 to 550 (3., until a pressure of about 50 atmospheres is attained. Then stop the supply of nitrogen and allow it to be absorbed by the lithlune-manganese nitrid, whereby the pressure drops'in accordance with the amount absorbed and is also dependent upon the size of the apparatus and the quantity of the mixture employed. It may be reduced to from, say, 30 to 4:0 atmospheres, or even less Then remove the nitrogen and pass hydrogen over the mixture. whereupon amthe gases leaving the vessel. This operation is also preferably carried out at a pressure of fifty atmospheres and at the' same temperature of from 450 to 550 C. employed in the first'part of the operation. When theformation of ammonia decreases, repeat the cycle of operations.

Instead of lithium-manganese nitrid,

other suitable mixtures as aforesaid can be employed, such for instance as nickel with molybdenum, or barium with chromium.

Now what we claim is 1. The process of producing ammonia by passing nitrogen and hydrogen successively and periodically over' a catalytic agent which contains a pluralitv of metals and which is capable of combining directly with at least one of the said gases nitrogen and hydrogen; 7

2. The process of producing ammonia by passing nitrogen and hydrogen successively and periodically over a catalytic agent which contains a plurality of metals, ,one of which belongs to the iron group, and which catalytic agent is capable of combining directly with one of the said gases, nitrogen and hydrogen.

3. The process of producing ammonia. by

passing nitrogen and hydrogen successively and periodically under pressure over a catalytic agent which contains a plurality of xnetels, of which one belongs to the iron group, and which catalytic agent ismapable of combining directly with one of the said gases, nitrogen and hydrogen. 1

4. The process of producing ammonia b passing nitrogen and hydrogen successively and periodically over a catalytic agent which contains lithium and manganese.

5.The process of producing ammonia by.

pessing nitrogen and hydrogen successively and periodlcall-y under pressure over aceta- I lytic agent which containslithiu n and manganese.

' 6. The process of producing ammonie by passing nitrogen and hydrogen successively and periodically under pressure over a catelytic agent which contains a plurality of metals and which is capable of combining directly with at least one of said gases, nitrogen and hydrogen.

In testimony whereof wqhiiiretliereunto set our hands in the presence of two subscribing witnesses.

I CARL BOSCH.

ALWIN MITTASCH.

Witnesses:

T. ALEC. LLOYD, Jos'nrrr PFEIFFER. 

